1. Field
This disclosure relates generally to memory systems, and more specifically, to method of operating an emulated electrically erasable (EEE) memory.
2. Related Art
Emulated electrically erasable (EEE) memories typically use a random access memory and a non-volatile memory that is electrically erasable combined to provide a memory system that has increased endurance over a regular non-volatile memory for a comparable size to that of the random access memory. This is achieved using a non-volatile memory much larger than the random access memory but EEE memory operates as if it were only the size of the random access memory. Thus the EEE memory emulates an electrically erasable memory of a reduced size from that which is used by the EEE memory but with an increase in endurance. This is useful in situations in which endurance is very important such as automotive applications in which data is updated often and must be stored in a non-volatile manner.
One problem common to EEE memories is that there can occasionally be long delays in being able to write data into the non-volatile memory because the too many locations in a sector in the non-volatile memory have data that is divided between valid data and invalid data. So before those locations can be written again, the sector must be erased but before the erase operation the locations with valid data must be written elsewhere. When this occurs there may an excessive amount of time required to perform all the necessary operations to perform the write operation.
Accordingly, there is a need to provide an EEE memory that improves upon the issue described above.